I needed to replace the plastic piston ring and came across this website. My requirements were for a 0.750" OD, 0.500" ID, 0.031" thick "piston ring". However, I was not content to use a teflon faucet washer that would require trimming. I did a bunch of online digging and came across this website:www.superiorwasher.comand found this product (T24-750031N-Pkg) which was EXACTLY what I needed.... up and running flawlessly.

I found a website that sells Teflon Washer and they were the perfect fit for me. 0.750" OD, 0.500" ID, 0.031" thick. Installed and running perfectly.www.superiorwasher.comT24-750031N-Pkg